Question

Average talk time between charges of a given cell phone is advertised as 4 hours. Let the standard deviation be 0.8 hour.a. Use Chebyshev’s theorem to approximate the proportion of cell phones that will have talk time between 2.4 hours and 5.6 hours.b. Assume a bell-shaped distribution to approximate the proportion of cell phones that will have talk time between 2.4 hours and 5.6 hours.